A liquid crystal display device includes a TFT substrate on which pixel electrodes and thin-film transistors (TFTs) or the like are formed in a matrix form, and a counter substrate opposed to the TFT substrate with a color filter or the like formed in alignment with the pixel electrodes on the TFT substrate. Liquid crystals are interposed between the TFT substrate and the counter substrate. An image is formed by controlling the light transmittance of liquid crystal molecules for each pixel.
A spacing (cell gap) between the TFT substrate and the counter substrate is accurately controlled by columnar spacers. Japanese Unexamined Patent Application Publication No. 2008-309857 describes a configuration in which first columnar spacers are always in contact with a counter substrate, and second columnar spacers come into contact with the counter substrate when a pressure is applied to the counter substrate. The first columnar spacers and the second columnar spacers are identical in height. The shape of a black matrix on the counter substrate keeps the first columnar spacers in contact with the counter substrate. With this configuration, the first columnar spacers keep the cell gap and prevent air bubbles at low temperatures while the second spacers control a pressure applied to a substrate surface.
Japanese Unexamined Patent Application Publication No. 2001-117103 describes a configuration in which the contact area of columnar spacers with a counter substrate is 0.05% to 0.15% in each pixel area, thereby simultaneously preventing cell gap variations and white spots appearing in the lower parts of the surfaces of a raised liquid crystal display panel.